The aim of the work was to quantify the role of runoff in nematode transport, compared with soil particle transport, during the rainy season in the Sudano-Sahelian area.
The measurements were made at the outlet of a 58 ha watershed located in the Nioro du Rip region, south of the Senegalese peanut-growing basin.
Every time the rainfall was sufficiently strong to cause a runoff, water was collected to estimate the volume of runoff, the soil particles and the nematode contents.
Soils in the different agronomic areas were also collected to determine the nematode infestation.
Some 6000 m3 of water run off during the rainy season, together with 18.6 t of soil and 279.5 million of nematodes, 127 million of which were major phytoparasitic species.
The transport of the different species was not uniform.
The first five runoff episodes supplied one-half the volume of runoff water and transported approximately half the phytoparasitic nematodes, but nearly three-quarters of the solid particles.
Fifteen percent of the nematodes were transported during the intermediate stage of the rainy season, and approximately 30% during the final period, with equivalent water proportions but smaller quantities of soil.
Of the 15 genera and species observed in the area, Tylenchorhynchus gladiolatus, Scutellonema cavenessi, Helicotylenchus dihystera and Gracilacus parvula represented 87% of the soil population, 61% being accounted for by the first two species. (...)
Mots-clés Pascal : Nematoida, Vermes, Invertebrata, Transport, Ruissellement, Soudan, Afrique Est, Afrique, Sahel, Sénégal, Afrique Ouest, Bassin versant, Ressource eau, Contamination, Erosion sol, Pluie, Nematodes, Parasite
Mots-clés Pascal anglais : Nematoida, worms, Invertebrata, transport, runoff, Sudan, East Africa, Africa, Sahel, Senegal, West Africa, drainage basins, water resources, contamination, soil erosion, rainfall
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0160565
Code Inist : 001E01O04. Création : 16/11/1999.